Material, article and method of preparing materials containing oriented anisotropic particles

Abstract

The present invention relates to a method for preparing oriented anisotropic particles comprising the steps of providing at least one anisotropic particle, dispersing the one anisotropic particle(s) in a medium, and freeze drying the dispersion of anisotropic particle(s) and the medium. In another embodiment, the present invention relates to an oriented anisotropic material comprising at least one anisotropic particle dispersed in a medium and thereafter freeze dried. Another embodiment relates to an article comprising an oriented anisotropic material and at least one matrix, wherein the oriented anisotropic material comprises a freeze dried anisotropic material.

1. An oriented anisotropic material comprising at least one anisotropic particle dispersed in a medium and thereafter freeze dried on a substrate, wherein said anisotropic particles are oriented by freeze drying perpendicular to said substrate. 
   
   
     2. The oriented anisotropic material of  claim 1  wherein said anisotropic particle comprise at least one member selected from the group consisting of silver salt grain, semiconducting, amorphous, crystalline, liquid crystalline, and metallic particles. 
   
   
     3. The oriented anisotropic material of  claim 1  wherein said anisotropic particle comprises fibers. 
   
   
     4. The oriented anisotropic material of  claim 1  wherein said anisotropic particle comprises anisotropic nanodevices. 
   
   
     5. The oriented anasotropic material of  claim 1  wherein said anisotropic particle comprises a layered particle. 
   
   
     6. The oriented anisotropic material of  claim 1  wherein said medium comprises at least one member selected from the group consisting of an aqueous medium and organic medium. 
   
   
     7. The oriented anisotropic material of  claim 1  wherein said medium comprises a dispersion of at least one dispersing polymer to splay said at least one anisotropic particle. 
   
   
     8. The oriented anisotropic material of  claim 7  wherein said splayed particle comprises an exfoliated particle. 
   
   
     9. The oriented anisotropic material of  claim 7  wherein said splayed particle comprises an intercalated particle. 
   
   
     10. The oriented anisotropic material of  claim 7  wherein said at least one dispersing polymer is water soluble. 
   
   
     11. The oriented anisotropic material of  claim 10  wherein said water soluble dispersing polymer is at least one member selected from the group consisting of gelatin, poly(vinyl alcohol), poly(ethylene oxide), polyvinylpyrrolidone, poly(acrylic acid), poly(styrene sulfonic acid), poly(acrylaniide), and quaternized polymer. 
   
   
     12. The oriented anisotropic material of  claim 7  wherein said dispersing polymer comprises a natural polymer. 
   
   
     13. The oriented anisolropic material of  claim 7  wherein said dispersing polymer comprises a synthetic polymer. 
   
   
     14. The oriented anisotropic material of  claim 13  wherein said dispersing polymer comprises at least one member selected from the group consisting of polyester, polyolefin, polystyrene, polyamide and thermoset polymer. 
   
   
     15. The oriented anisotropic material of  claim 14  wherein said thermoset dispersing polymer is at least one member selected from the group consisting of polyester, unsaturated polyester, alkyd, phenolic, amino plastic, epoxy resin, polyurethane and polysulfide. 
   
   
     16. The oriented anisotropic material of  claim 1  wherein said anisotropic material has anisotropy factor of at least 1.2. 
   
   
     17. An article comprising an oriented anisotropic material and at least one matrix, wherein said oriented anisotropic material comprises anisotropic particles freeze dried on a substrate, wherein said anisotropic particles are oriented by freeze drying perpendicular to said substrate. 
   
   
     18. The article of  claim 17  wherein said matrix comprises at least one polymer. 
   
   
     19. The article of  claim 18  wherein said polymer comprises a natural polymer. 
   
   
     20. The article of  claim 18  wherein said polymer comprises a synthetic polymer. 
   
   
     21. The article of  claim 20  wherein said matrix polymer comprises at least one member selected from the group consisting of polyester, polyolefin, polystyrene, polyamide, and thermoset polymer. 
   
   
     22. The article of  claim 21  wherein said thermoset polymer is at least one member selected from the group consisting of polyester, unsaturated polyester, alkyd, phenolic, amino plastic, epoxy resin, polyurethane and polysulfide. 
   
   
     23. The article of  claim 18  wherein said at least one polymer is water soluble. 
   
   
     24. The article of  claim 23  wherein said water soluble polymer is at least one member selected from the group consisting of gelatin, poly(vinyl alcohol), poly(ethylene oxide), polyvinylpyrrolidone, poly(acrylic acid), poly(styrene sulfonic acid), poly(acrylamide, and quaternized polymer. 
   
   
     25. The article of  claim 17  wherein said anisotropic particle is at least one member selected from the group consisting of silver salt grains, semiconducting particles, amorphous, crystalline, liquid crystalline, and metallic particles. 
   
   
     26. The article of  claim 17  wherein said anisotropic particle comprises fibers. 
   
   
     27. The article of  claim 17  wherein said anisotropic particle comprises anisotropic nanodevices. 
   
   
     28. The article of  claim 17  wherein said anisotropic particle comprises a layered particle. 
   
   
     29. The article of  claim 17  wherein said freeze dried anisotropic material comprises anisotropic particles splayed with at least one polymer. 
   
   
     30. The oriented anisotropic material of  claim 17  wherein said anisotropic material has anisotropy factor of at least 1.2. 
   
   
     31. An oriented anisotropic material comprising at least one anisotropic particle dispersed in a synthetic thermoset polymer and thereafter freeze dried, wherein said oriented anisotropic material has an anisotropy factor of at least 1.2. 
   
   
     32. The oriented anisotropic material of  claim 31  wherein said anisotropic particle comprise at least one member selected from the group consisting of silver salt grain, semiconducting, amorphous, crystalline, liquid crystalline, and metallic particles. 
   
   
     33. The oriented anisotropic material of  claim 31  wherein said anisotropic particle comprises fibers. 
   
   
     34. The oriented anisotropic material of  claim 31  wherein said anisotropic particle comprises anisotropic nanodevices. 
   
   
     35. The oriented anisotropic material of  claim 31  wherein said anisotropic particle comprises a layered particle. 
   
   
     36. The oriented anisotropic material of  claim 31  wherein said splayed particle comprises an exfoliated particle. 
   
   
     37. The oriented anisotropic material of  claim 31  wherein said splayed particle comprises an intercalated particle. 
   
   
     38. The oriented anisotropic material of  claim 31  wherein said at least one dispersing polymer is water soluble. 
   
   
     39. The oriented anisotropic material of  claim 38  wherein said water soluble dispersing polymer is at least one member selected from the group consisting of gelatin, poly(vinyl alcohol), poly(ethylene oxide), polyvinylpyrrolidone, poly(acrylic acid), poly(styreme sulfonic acid), poly(acrylamide), and quaternized polymer. 
   
   
     40. The oriented anisotropic material of  claim 31  wherein said thermoset dispersing polymer is at least one member selected from the group consisting of polyester, unsaturated polyester, alkyd, phenolic, amino plastic, epoxy resin, polyurethane and polysulfide.